Optimal durations of single exposures to a frequency-modulated magnetic field immediately after bisection in planarian predict final growth values.

Planarian (Dugesia tigrinia) were exposed to a frequency-modulated ("Thomas"), patterned electromagnetic field (EMF) immediately following transection through the pharynx. Subjects were exposed from 15 min to 3 h as well as single versus repeated exposures. Results from multiple experiments indicated that those planaria exposed from 45 to 90 min regenerated at significantly higher rates than those exposed less than 45 min. In addition, the study revealed that exposures greater than 45 min were not significantly different beyond this inflection point. We suggest that this particular pattern of EMF is capable of inducing biochemical pathways associated with cell proliferation, in particular the p38-MAPK and hsp70 pathways.